<div class="list-group padding-h-neg">
  <div class="alert alert-info" *ngIf="!items?.length">
    没有找到符合条件的文章
  </div>
  <a [routerLink]="['./', item.id]" class="list-group-item" *ngFor="let item of items">
    {{item.title}}   <small class="text-muted">[{{item.authors}}]</small>
  </a>
</div>
